[API Review] RT-27887: introduce a node to embed Swing into JavaFX

[Richard Bair]

>> IMO this is wrong. I firmly believe that FX APIs should be callable on
>> either the FX Event Thread only, or any thread, depending on the API's
>> specification. Adding an FX API that can only be invoked on a specific
>> thread of another GUI toolkit doesn't seem right to me.
> 
> I agree with you and I understood Richards comment like this as well.
> JavaFX APIs must be callable always at least on the FX-Thread.

That's correct, that was my sentiment as well.